Introduction: A t was conducted by Meeran Rani in the partial fulfillment of the requirement of M.Sc. Nursing degree course at descriptive study to assess the knowledge regarding prevention of acne vulgaris among the adolescents at Govt. Model Girls Senior Secondary School Portmore in Shimla (H.P.) with the view to develop information bookle Sngnc, IGMC Shimla. Objectives: 1) To assess the knowledge regarding prevention of acne vulgaris among the adolescents 2) To determine the association of knowledge with selected demographic variables 3) To develop an information booklet. Method: A descriptive research design was chosen, convenient sampling technique was used to select 100 sample for the study. The tool used for study was structured knowledge questionnaires to assess the knowledge regarding prevention of acne vulgaris . Independent variable of the study was structured knowledge questionnaires and dependent variable was knowledge of student regarding prevention acne vulgaris. The data gathered was analyzed and interpreted in the light of objectives by using the descriptive and inferential statistics in terms of frequency, percentage, mean, median and S.D chi – square, and to find out the significance of certain variables. Bar diagram and pie diagram used to depict the findings. Results: The major finding of the study revealed that knowledge regarding acne vulgaris prevention was good. Study results revealed that in average, knowledge was 90%, good knowledge was 7% and 3% had poor knowledge. None had very good knowledge regarding acne vulgaris. Mean was 16.01 median score was 17, S.D. 3.06 maximum 22, minimum 9, range 13, mean percentage was 53. 37. None of the group had poor practice of mean score of maximum number of adolescents 86% were in the age group of 15-16 years, followed by 12%were under age group of 17-18 years and 2%were under the age group of 13-14 years but none of them were under the age group of 19-20 years . All the adolescents were Female that is 100%. Majority of adolescents 97% were Hindu, followed by 2% were Muslim and the least 1% were others but none of them were Christian. Majority of the adolescents 64% belonged to urban residence and 36% belonged to rural residence. Most of the adolescents 86% were studying in 11th class, followed by 8% belonged to 10th class and the least 6% belonged to 12th class. Majority of the adolescents had 37% family income of 15001Rs. or above, followed by 26% belonged to family income between 5001-10000 Rs, followed by 22% belonged to family income between 1000-5000 and the least 15% belonged to family income between 10001-15000 Rs. Most of the adolescents 80% were vegetarian, followed by 20% were non-vegetarian. Majority of the adolescents 61% had some previous knowledge, followed by 24% didn’t had any previous knowledge and the least 15% had some knowledge regarding prevention of acne vulgaris. Majority of the adolescents 32% had family, followed by 27% had friends, followed by 24% had mass media and the least 17 % had others as source of information regarding prevention of acne vulgaris.